The present invention relates to the area of chemotherapeutic agents and, more particularly, relates to certain substituted polyketides, and the use of said polyketides in treating tumors.
Cancer is a serious health problem throughout the world. For example, cancer incidence in the U.S. has increased 30% during the past 30 years, and is expected to continue to increase into the next century. This is attributable to the increased prevalence of cigarette smoking in women compared to men, general aging of the population, and enhanced diagnostic capabilities, as well as potential decreases in mortality from other causes. As a result, an extensive number of research endeavors has been undertaken in an effort to develop therapies appropriate to the treatment and alleviation of cancer in humans.
In the chemotherapeutic area, research has been conducted to develop anti-tumor agents effective against various types of cancer. Oftentimes, anti-tumor agents which have been developed and found effective against cancer cells are, unfortunately, also toxic to normal cells. This toxicity manifests itself in weight loss, nausea, vomiting, hair loss, fatigue, itching, hallucinations, loss of appetite, etc., upon administration of the anti-tumor agent to a patient in need of cancer chemotherapy.
Furthermore, conventionally used chemotherapeutic agents do not have the effectiveness desired or are not as broadly effective against different types of cancers as desired. As a result, a great need exists for chemotherapeutic agents which are not only more effective against all types of cancer, but which have a higher degree of selectivity for killing cancer cells with no or minimal effect on normal healthy cells. In addition, highly effective and selective anti-tumor agents, in particular, against cancers of the colon, bladder, prostate, stomach, pancreas, breast, lung, liver, brain, testis, ovary, cervix, skin, vulva and small intestine are desired. Moreover, anti-tumor activity against colon, breast, lung and prostate cancers as well as melanomas are particularly desired because of the lack of any particular effective therapy at the present time.
(+)-Discodermolide is a novel polyketide natural product that was isolated from extracts of the marine sponge Discodermia dissoluta by researchers at the Harbor Branch Oceanographic Institution (HBOI) (Gunasekera S P, Gunasekera M, Longley R E, Schulte G K. Discodermolide: a new bioactive polyhydroxylated lactone from the marine sponge Discodermia dissoluta. [published erratum appears in J. Org. Chem. 1991;56:1346]. J. Org. Chem. 1990;55:4912-15.). Discodermolide lacks obvious structural resemblance to paclitaxel, yet it shares with paclitaxel (the active substance in the drug Taxol) the ability to stabilize microtubules. In mechanism-based assays, discodermolide is more effective than paclitaxel. In fact, of the handful of compounds known to induce polymerization of purified tubulin, discodermolide is the most potent. However, microtubules, the major structural component in cells, are not simple equilibrium polymers of tubulin. They exist as regulated GTP-driven dynamic assemblies of heterodimers of xcex1 and xcex2 tubulin. Although the dynamics are relatively slow in interphase cells, upon entering mitosis, the rate of growing and shortening increases 20- to 100-foldxe2x80x94the average microtubule turns over half the tubulin subunits every ten seconds. This change in rate allows the cytoskeletal microtubule network to dismantle and a bipolar spindle-shaped array of microtubules to assemble. The spindle attaches to chromosomes and moves them apart. The response to complete suppression of microtubule dynamics in cells is death. However, mitotic cells are more sensitive and the tolerance threshold appears to be cell-type specific. Molecules like paclitaxel that bind with high affinity to microtubules disrupt the dynamics process in tumor cells with lethal results even when the ratio of bound drug to tubulin is very low. Discodermolide binds to tubulin competitively with paclitaxel. Since paclitaxel has proven to be useful in treating some cancers, other compounds of the same mechanistic class may have utility against hyperproliferative disorders.
Development of discodermolide or structurally related analogues is hindered by the lack of a reliable natural source of the compound or a feasible synthetic route. Naturally occurring discodermolide is scarce and harvesting the producing organism presents logistical problems. There is an ever-growing need for improved syntheses that enable production of multi-gram amounts of discodermolide and structurally related analogues.
Martello L A, LaMarche M J, He L, Beauchamp T J, Smith A B, Horwitz S B. The relationship between Taxol and (+)-discodermolide: synthetic analogs and modeling studies. Chem. Biol. 2001;8(9):843-855.
Nerenberg J B, Hung D T, Somers P K, Schreiber S L. Total synthesis of the immunosuppressive agent (xe2x88x92)-discodermolide. J. Am. Chem. Soc. 1993;115:12621-622.
Hung D T, Nerenberg J B, Schreiber S L. Syntheses of discodermolides useful for investigating microtubule binding and stabilization. J. Am. Chem. Soc. 1996;118:11054-11080.
Smith A B, Qiu Y, Jones D R, Kobayashi K. Total synthesis of (xe2x88x92)-discodermolide. J. Am. Chem. Soc. 1995; 117:12011-12012.
Harried S S, Yang G, Strawn M A, Myles D C. Total synthesis of (xe2x88x92)-discodermolide: an application of a chelation-controlled alkylation reaction., J. Org. Chem. 1997;62:6098-6099.
Marshall J A, Johns B A. Total synthesis of (+)-discodermolide. J. Org. Chem. 1998;63:7885-7892.
Halstead D P. I. Total synthesis of (+)-miyakolide II. Total synthesis of (xe2x88x92)-discodermolide III. Total synthesis of (+)-discodermolide (dissertation). Cambridge (Mass): Harvard University, 1998.
Smith A B III, Kaufman M D, Beauchamp T J, LaMarche M J, Arimoto H. Gram-Scale Synthesis of (+)-Discodermolide. Org. Lett. 1999;1:1823-1826.
Paterson I, Florence G J, Gerlach K, Scott J. Total synthesis of the antimicrotubule agent (+)-discodermolide using boron-mediated aldol reactions of chiral ketones. Angew. Chem., Int. Ed. 2000;39:377-380.
Smith A B III, Qiu Y, Kaufman M, Arimoto H, Jones D R, Kobayashi K, Beauchamp T J. Preparation of intermediates for the synthesis of discodermolides and their polyhydroxy dienyl lactone derivatives for pharmaceutical use. U.S. (2000), 83 pp., Cont.-in-part of U.S. Pat. No. 5,789,605. CODEN: USXXAM U.S. Pat. No. 6,096,904 A 20000801 CAN 133:135166 AN 2000:531688.
Smith A B III, Qiu Y, Kaufman M, Arimoto H, Jones D R, Kobayashi K, Beauchamp, T J. Preparation of intermediates for the synthesis of discodermolides and their polyhydroxy dienyl lactone derivatives for pharmaceutical use. PCT Int. Appl. (2000), 201 pp. CODEN: PIXXD2 WO 0004865 A2 20000203 CAN 132:137207 AN 2000:84572.
Smith A B III Qiu Y, Kaufman M, Arimoto H, Jones D R, Kobayashi K. Synthetic techniques and intermediates for polyhydroxydienyllactones and mimics thereof. PCT Int. Appl. (1998), 194 pp. CODEN: PIXXD2 WO 9824429 A1 19980611 CAN 129:67649 AN 1998:394202.
Gunasekera S P, Longley R E. Synthesis, antitumor activity and formulations of discodermolide acetates. U.S. (2000), 9 pp. CODEN: USXXAM U.S. Pat. No. 6,127,406 A 20001003 CAN 133:281651 AN 2000:699192.
The present invention provides new anti-tumor agents which are effective against a variety of cancer cells. More particularly, the present invention relates to certain substituted polyketides which exhibit a higher degree of selectivity in killing cancer cells. In addition, the present invention provides pharmaceutical compositions useful in treating tumors comprising a therapeutically effective amount of a certain substituted polyketide. Moreover, the present invention provides a method of treating tumors comprising administering to a mammal afflicted therewith a therapeutically effective amount of a certain substituted polyketide.
The essence of the instant invention is the discovery that certain substituted polyketides are useful in treating tumors. In one embodiment, the instant invention provides new anti-tumor agents of formula I: 
where A is xe2x80x94CHxe2x95x90C(R1)CH2xe2x80x94, xe2x80x94CH2N(R2)C(O)xe2x80x94, xe2x80x94C(O)N(R2)CH2xe2x80x94, xe2x80x94CH2N(R2)CH2xe2x80x94, xe2x80x94CH2N(CO2R3)CH2xe2x80x94 or xe2x80x94CH2N(COR2)CH2xe2x80x94;
B is xe2x80x94CH(R1)CHxe2x95x90CHCHxe2x95x90CH2, xe2x80x94CH(R2)R1, xe2x80x94CH(R1)CHxe2x95x90CHR2, xe2x80x94CH(R1)CHxe2x95x90CHC(O)OR2, xe2x80x94CH(R1)CHxe2x95x90CHC(O)N(R1)R2, xe2x80x94CH(R1)CH2OR2 or Ar;
C is H, xe2x80x94C(O)N(R1)R2, xe2x80x94C(O)NHCH2(CH2)nN(CH3)2 or xe2x80x94C(O)NHCH2(CH2)n-4-morpholino;
R1 is H or (C1-6)alkyl;
R2 is H, (C1-6)alkyl, (C2-6)alkenyl, (C2-6)alkynyl, (C1-6)alkyl-Ar or Ar;
R3 is (C1-6)alkyl, (C1-6)alkyl-Ar or Ar;
Ar is an aromatic or heteroaromatic ring selected from 
R4 and R5 are,
independently, H, (C1-6)alkyl, OH, O(C1-6)alkyl, OCH2(CH2)nOH, O(CH2)nCO2H, OCH2(CH2)nN(CH3)2, OCH2(CH2)n-4-morpholino, F, Cl, Br or CF3; and
n is 1 or 2;
with the proviso that when A is xe2x80x94CHxe2x95x90C(CH3)CH2xe2x80x94 or xe2x80x94CHxe2x95x90CHCH2xe2x80x94,
then either:
B cannot be xe2x80x94CH(CH3)CHxe2x95x90CHCHxe2x95x90CH2, xe2x80x94CH(CH3)CH2Ph, xe2x80x94CH(CH3)Ph, xe2x80x94CH(CH3)-n-Bu, 
or C cannot be xe2x80x94C(O)N(R1)R2 or H;
or an acid or base addition salt thereof, where possible.
Preferred compounds are those of formula Ia: 
where Axe2x80x2 is xe2x80x94CHxe2x95x90C(R1xe2x80x2)CH2xe2x80x94, xe2x80x94CH2N(R2xe2x80x2)C(O)xe2x80x94, xe2x80x94C(O)N(R2xe2x80x2)CH2xe2x80x94, xe2x80x94CH2N(CO2R3xe2x80x2)CH2xe2x80x94 or xe2x80x94CH2N(COR2xe2x80x2)CH2xe2x80x94;
Bxe2x80x2 is xe2x80x94CH(R1xe2x80x2)CHxe2x95x90CHCHxe2x95x90CH2, xe2x80x94CH(R2xe2x80x2)R1xe2x80x2, xe2x80x94CH(R1xe2x80x2)CHxe2x95x90CHR2xe2x80x2, xe2x80x94CH(R1xe2x80x2)CH2OR2xe2x80x2 or Arxe2x80x2;
Cxe2x80x2 is H, xe2x80x94C(O)N(R1xe2x80x2)R2xe2x80x2, xe2x80x94C(O)NHCH2(CH2)nN(CH3)2 or xe2x80x94C(O)NHCH2(CH2)n-4-morpholino;
R1xe2x80x2 is H or (C1-6)alkyl;
R2xe2x80x2 is H, (C1-6)alkyl, (C2-6)alkenyl, (C2-6)alkynyl, (C1-6)alkyl-Arxe2x80x2 or Arxe2x80x2;
R3xe2x80x2 is (C1-6)alkyl, (C1-6)alkyl-Arxe2x80x2 or Arxe2x80x2;
Arxe2x80x2 is an aromatic or heteroaromatic ring selected from 
R4xe2x80x2 and R5xe2x80x2 are,
independently, H, (C1-6)alkyl, OH, O(C1-6)alkyl, OCH2(CH2)nOH, O(CH2)nCO2H, OCH2(CH2)nN(CH3)2, OCH2(CH2)n-4-morpholino, F, Cl, Br or CF3; and
n is 1 or 2;
with the proviso that when Axe2x80x2 is xe2x80x94CHxe2x95x90C(CH3)CH2xe2x80x94 or xe2x80x94CHxe2x95x90CHCH2xe2x80x94,
then either:
Bxe2x80x2 cannot be xe2x80x94CH(CH3)CHxe2x95x90CHCHxe2x95x90CH2, xe2x80x94CH(CH3)CH2Ph, xe2x80x94CH(CH3)Ph, xe2x80x94CH(CH3)-n-Bu, 
or Cxe2x80x2 cannot be xe2x80x94C(O)N(R1xe2x80x2)R2xe2x80x2 or H;
or an acid or base addition salt thereof, where possible.
More preferred compounds are those of formula Ib: 
where Axe2x80x3 is xe2x80x94CHxe2x95x90C(R1xe2x80x3)CH2xe2x80x94, xe2x80x94CH2N(R2xe2x80x3)C(O)xe2x80x94 or xe2x80x94C(O)N(R2xe2x80x3)CH2xe2x80x94;
Bxe2x80x3 is xe2x80x94CH(R1xe2x80x3)CHxe2x95x90CHCHxe2x95x90CH2, xe2x80x94CH(R2xe2x80x3)R1xe2x80x3, xe2x80x94CH(R1xe2x80x3)CHxe2x95x90CHR2xe2x80x3, xe2x80x94CH(R1xe2x80x3)CH2OR2xe2x80x3 or Arxe2x80x3;
Cxe2x80x3 is H, xe2x80x94C(O)N(R1xe2x80x3)R2xe2x80x3, xe2x80x94C(O)NHCH2(CH2)nN(CH3)2 or xe2x80x94C(O)NHCH2(CH2)n-4-morpholino;
R1xe2x80x3 is H or xe2x80x94CH3;
R2xe2x80x3 is H, (C1-6)alkyl, (C2-6)alkenyl, (C2-6)alkynyl, (C1-6)alkyl-Arxe2x80x3 or Arxe2x80x3;
Arxe2x80x3 is an aromatic or heteroaromatic ring selected from 
R4xe2x80x3 and R5xe2x80x3 are,
independently, H, (C1-6)alkyl, OH, O(C1-6)alkyl, OCH2(CH2)nOH, O(CH2)n, CO2H, OCH2(CH2), N(CH3)2, OCH2(CH2)n-4-morpholino, F, Cl, Br or CF3; and
n is 1 or 2;
with the proviso that when Axe2x80x3 is xe2x80x94CHxe2x95x90C(CH3)CH2xe2x80x94 or xe2x80x94CHxe2x95x90CHCH2xe2x80x94,
then either:
Bxe2x80x3 cannot be xe2x80x94CH(CH3)CHxe2x95x90CHCHxe2x95x90CH2, xe2x80x94CH(CH3)CH2Ph, xe2x80x94CH(CH3)Ph, xe2x80x94CH(CH3)-n-Bu, 
or Cxe2x80x3 cannot be xe2x80x94C(O)N(R1xe2x80x3)R2xe2x80x3 or H;
or an acid or base addition salt thereof, where possible.
Even more preferred compounds are those of formula Ic: 
where Axe2x80x2xe2x80x3 is xe2x80x94CHxe2x95x90C(R1xe2x80x2xe2x80x3)CH2xe2x80x94, xe2x80x94CH2N(R2xe2x80x2xe2x80x3)C(O)xe2x80x94 or xe2x80x94C(O)N(R2xe2x80x2xe2x80x3)CH2xe2x80x94;
Bxe2x80x2xe2x80x3 is xe2x80x94CH(R1xe2x80x2xe2x80x3)CHxe2x95x90CHCHxe2x95x90CH2, xe2x80x94CH(R2xe2x80x2xe2x80x3)R1xe2x80x2xe2x80x3, xe2x80x94CH(R1xe2x80x2xe2x80x3)CHxe2x95x90CHR2xe2x80x2xe2x80x3, xe2x80x94CH(R1xe2x80x2xe2x80x3)CH2OR2xe2x80x2xe2x80x3 or Arxe2x80x2xe2x80x3;
Cxe2x80x2xe2x80x3 is H or xe2x80x94C(O)N(R1xe2x80x2xe2x80x3)R2xe2x80x2xe2x80x3;
R1xe2x80x2xe2x80x3 is H or CH3;
R2xe2x80x2xe2x80x3 is H, (C1-6)alkyl, (C2-6)alkenyl, (C2-6)alkynyl, (C1-6)alkyl-Arxe2x80x2xe2x80x3 or Arxe2x80x2xe2x80x3;
Arxe2x80x2xe2x80x3 is an aromatic ring having the formula 
R4xe2x80x2xe2x80x3 and R5xe2x80x2xe2x80x3 are,
independently, H, (C1-6)alkyl, OH, O(C1-6)alkyl, F, Cl, Br or CF3;
with the proviso that when Axe2x80x2xe2x80x3 is xe2x80x94CHxe2x95x90C(CH3)CH2xe2x80x94 or xe2x80x94CHxe2x95x90CHCH2xe2x80x94,
then either:
Bxe2x80x2xe2x80x3 cannot be xe2x80x94CH(CH3)CHxe2x95x90CHCHxe2x95x90CH2, xe2x80x94CH(CH3)CH2Ph, xe2x80x94CH(CH3)Ph, xe2x80x94CH(CH3)-n-Bu, 
or Cxe2x80x2xe2x80x3 cannot be xe2x80x94C(O)N(R1xe2x80x2xe2x80x3)R2xe2x80x2xe2x80x3 or H;
or an acid or base addition salt thereof, where possible.
In another embodiment, the instant invention provides pharmaceutical compositions useful in treating tumors comprising a pharmaceutically acceptable carrier or diluent and a therapeutically effective amount of a compound of formula I above, or a pharmaceutically acceptable acid or base addition salt thereof, where possible, preferably a compound of formula Ia above, or a pharmaceutically acceptable acid or base addition salt thereof, where possible, more preferably a compound of formula Ib above, or a pharmaceutically acceptable acid or base salt thereof, where possible, and even more preferably a compound of formula Ic above, or a pharmaceutically acceptable acid or base addition salt thereof, where possible.
In still another embodiment, the instant invention provides a method for treating tumors comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound of formula I above, or a pharmaceutically acceptable acid or base addition salt thereof, where possible, preferably a compound of formula Ia above, or a pharmaceutically acceptable acid or base addition salt thereof, where possible, more preferably a compound of formula Ib above, or a pharmaceutically acceptable acid or base addition salt thereof, where possible, and even more preferably a compound of formula Ic above, or a pharmaceutically acceptable acid or base addition salt thereof, where possible.
In the above definitions: 1) the alkyl groups containing 1 to 6 carbon atoms are either straight or branched chain or cycloalkane, of which examples include isopropyl, isobutyl, t-butyl, isopentyl, neopentyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 1,1,2,2-tetramethylethyl, cyclopentyl and cyclohexyl.
Although the pharmaceutically acceptable acid or base addition salts are preferred, it should be understood that all of the acid or base addition salts of the compounds of formula I are intended to be included within the scope of the present invention.
The acid addition salts of the compounds of formula I may be those of pharmaceutically acceptable organic or inorganic acids. Although the preferred acid addition salts are those of hydrochloric and methanesulfonic acid, salts of sulfuric, phosphoric, citric, fumaric, maleic, benzoic, benzenesulfonic, succinic, tartaric, lactic and acetic acid may also be utilized.
Likewise, the base addition salts of the compounds of formula I may be those of pharmaceutically acceptable organic or inorganic bases. Preferred base addition salts are those derived from pharmaceutically acceptable inorganic bases, more preferably ammonium hydroxide or an alkali or alkaline earth metal hydroxide, e.g, lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide and manganese hydroxide.
The substituted polyketides of formula I may be prepared as depicted below. In the event that the groups A-F contain free hydroxy groups, then the asterisk designation (e.g., A*) indicates that those groups are protected with acid labile protecting groups (e.g., TBS). All acid labile protecting groups covered by the asterisk are removed in the final step (HCl). 
As to the individual steps in Scheme 1, Step A involves the addition of a ketone of formula 2 to an aldehyde of formula 1 to obtain a hydroxyketone of formula 3. The addition requires between 1 and 20 equivalents of 2 relative to aldehyde 1, preferably between 5 and 15 equivalents of 2 relative to aldehyde 1. The coupling is conducted in the presence of: 1) a dialkylboron halide or triflate, preferably a chiral boron chloride or triflate, more preferably B-chlorodiisopinocampheylborane; 2) a base, preferably an amine, more preferably triethylamine; and 3) a polar organic solvent, preferably an ether, more preferably diethyl ether, at a temperature of between xe2x88x92100xc2x0 C. and 20xc2x0 C., preferably between xe2x88x9278xc2x0 C. and xe2x88x9220xc2x0 C., for a period of between 2 and 72 hours, preferably for 16 hours.
Step B concerns the reduction of the hydroxyketone of formula 3, to obtain a 1,3-diol compound of formula 4. The reduction is conducted in the presence of: 1) a ketone reducing agent, preferably a borohydride such as tetramethylammonium triacetoxyborohydride; 2) a polar organic solvent, preferably acetonitrile; and 3) a protic solvent, preferably a carboxylic acid, such as acetic acid, at a temperature of between xe2x88x9278xc2x0 C. and 20xc2x0 C., preferably between xe2x88x9240xc2x0 C. and xe2x88x9210xc2x0 C., for a period of between 2 and 72 hours, preferably for 16 hours.
Step C concerns the hydrolysis and cyclization of the 1,3-diol compound 4 to a substituted polyketide of formula 5. The hydrolysis reaction is conducted in the presence of: 1) a protic acid, preferably an aqueous protic acid solution, preferably an aqueous hydrogen halide solution, such as aqueous hydrogen chloride; and 2) a polar organic solvent, preferably a mixture of polar organic solvents, preferably a mixture of an aliphatic alcohol and an ether, such as methanol and tetrahydrofuran, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably between 20xc2x0 C. and 25xc2x0 C., for a period of 8 hours and 7 days, preferably between 16 and 72 hours, more preferably between 24 and 48 hours. 
As to the individual steps in Scheme 2, Step A involves the oxidative hydrolysis of a para-methoxybenzyl ether of formula 1 to a diol of formula 2. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour.
Step B involves the oxidation of an alcohol of formula 2 to obtain an aldehyde of formula 3. The oxidation is conducted in the presence of: 1) an oxidizing reagent, preferably a mild oxidizing reagent such as the combinations of oxalyl chloride, DMSO and triethylamine; sulfur trioxide-pyridine complex, DMSO and triethylamine; and 2,2,6,6-tetramethyl-1-piperidinyloxy free radical and diacetoxyiodobenzene; and 2) an inert organic solvent, preferably a polar organic solvent such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step C involves the olefination of an aldehyde of formula 3 with an olefinating reagent, preferably (CF3CH2O)2P(O)CH2CO2CH3, to obtain an olefin of formula 4. The olefination is conducted in the presence of: 1) a strong base, preferably an alkali metal salt such as potassium hexamethyldisilazide or butyllithium; and 2) an inert organic solvent, preferably a hydrocarbon such as toluene, or an ether such as tetrahydrofuran, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step D concerns the carbamoylation of the olefin of formula 4 with an isocyanate either of formula C*NCO or Cl3C(O)NCO to give a carbamate of formula 5. In the case of using C*NCO, the carbamoylation is conducted in the presence of a Lewis acid such as Bu2Sn(OAc)2 or a weak base such as triethylamine, in a polar aprotic solvent, preferably a halogenated solvent such as methylene chloride at a temperature of between xe2x88x9220xc2x0 C. and 100xc2x0 C., preferably between 0xc2x0 C. and 50xc2x0 C., for a period of between 5 minutes and 72 hours, preferably between 1 hour and 24 hours. In the case using Cl3C(O)NCO, which produces substituted polyketides of formula I where Cxe2x95x90H, the carbamoylation is conducted in the presence of a polar aprotic solvent, preferably a halogenated solvent such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 100xc2x0 C., preferably at 25xc2x0 C., for a period of between 5 minutes and 72 hours, preferably between 1 hour and 8 hours; the work-up of this step is conducted in the presence of a protic organic solvent, preferably an alcohol such as methanol, in the presence of a base, for example, a carbonate such as potassium carbonate, at a temperature of between between 0xc2x0 C. and 100xc2x0 C., preferably at 25xc2x0 C., for a period of between 5 minutes and 72 hours, preferably between 1 hour and 8 hours.
Step E involves the reduction of a carbamate of formula 5 to obtain an alcohol of formula 6. The reduction is conducted in the presence of: 1) a reducing reagent, preferably an aluminum hydride reagent such as diisobutylaluminum hydride; and 2) an inert organic solvent, preferably a polar organic solvent such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 0xc2x0 C., preferably at xe2x88x9278xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours.
Step F involves the oxidation of an alcohol of formula 6 to obtain an aldehyde of formula 7. The oxidation is conducted in the presence of: 1) an oxidizing reagent, preferably a mild oxidizing reagent such as the Dess-Martin periodinane reagent; or the combinations of oxalyl chloride, DMSO and triethylamine; sulfur trioxide-pyridine complex, DMSO and triethylamine; and 2,2,6,6-tetramethyl-1-piperidinyloxy free radical and diacetoxyiodobenzene; and 2) an inert organic solvent, preferably a polar organic solvent such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for a period of between 1 and 3 hours. 
As to the individual steps in Scheme 3, Step A involves the reduction of a cyclic para-methoxyphenyl acetal of formula 1 to obtain an alcohol of formula 2. The reduction is conducted in the presence of: 1) a metal hydride, preferably an aluminum hydride such as diisobutylaluminum hydride; and 2) an aprotic organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 10xc2x0 C., preferably from xe2x88x9278xc2x0 C. to 0xc2x0 C., for a period of between 10 minutes and 8 hours, preferably for 2 hours.
Step B involves the etherification of an alcohol of formula 2 to obtain an ether of formula 3. The etherification is conducted in the presence of: 1) an alcohol of formula R2*OH, where R2* is as described above; 2) a coupling reagent such as diethyl azodicarboxylate; 3) a phosphine such as triphenylphosphine; and 4) a polar organic solvent, such tetrahydrofuran, at a temperature of between xe2x88x9278xc2x0 C. and 60xc2x0 C., preferably between xe2x88x9220xc2x0 C. and 40xc2x0 C., for a period of between 2 and 72 hours, preferably for 16 hours. Alternatively, R2*OH is replaced with an R2*halide or R2*sulfonate. In this case, the etherification is conducted in the presence of: 1) a base, preferably an alkali metal base, such as sodium hydride; 2) a polar organic solvent, such as N,N-dimethylformamide; and 3) an optional catalytic amount of an iodide salt, such as potassium iodide, at a temperature of between xe2x88x9278xc2x0 C. and 60xc2x0 C., preferably between xe2x88x9220xc2x0 C. and 40xc2x0 C., for a period of between 2 and 72 hours, preferably for 16 hours.
Step C involves the oxidative hydrolysis of an ether of formula 3 to a diol of formula 4. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 4, Step A involves the palladium-mediated coupling of an alkyl iodide of formula 1 and a vinyl iodide of formula 2 to obtain an alkene of formula 3. The palladium-mediated coupling is conducted in the presence of: 1) a hindered organometallic reagent, preferably a hindered organolithium reagent such as t-butyllithium; 2) either a zinc halide such as zinc chloride or a hindered boron reagent such as 9-methoxy-9-borabicyclo[3.3.1]nonane; 3) a palladium reagent such as tetrakis(triphenylphosphine)palladium(0) or [1,1xe2x80x2-bis(diphenylphosphino)ferrocene]-dichloropalladium(II); and 4) a polar organic solvent, preferably an ether such as diethyl ether, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., for a period of between 1 hour and 72 hours.
Step B involves the oxidative hydrolysis of an alkene of formula 3 to a diol of formula 4. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 5, Step A involves the olefination of an aldehyde of formula 2 with a phosphonium salt of formula 1 to obtain an alkene of formula 3. The olefination is conducted in the presence of: 1) a strong base, preferably an alkali metal salt such as potassium hexamethyldisilazide or butyllithium; and 2) an inert organic solvent, preferably a hydrocarbon such as toluene, or an ether such as tetrahydrofuran, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step B involves the oxidative hydrolysis of an alkene of formula 3 to a diol of formula 4. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 6, Step A involves the reductive amination of an aldehyde of formula 1 to obtain an amine of formula 2. The reductive amination is conducted in the presence of: 1) an amine of formula R5NH2 where R5 is as defined above; 2) a reducing agent, preferably a hydride, more preferably a borohydride salt such as sodium borohydride; and 3) a polar organic solvent, preferably a protic organic solvent such as ethanol, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably from 5xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 16 hours.
Step B involves the acylation of an amine of formula 2 to obtain an amide of formula 4. The acylation is conducted in the presence of: 1) a carboxylic acid of formula 3; 2) a carboxylic acid coupling reagent, preferably a diimide such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and a suitable activating agent common to diimide coupling reactions, such as 1-hydroxybenzotriazole; and 3) a polar organic solvent, preferably a low molecular weight amide such as DMF, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 and 24 hours.
Step C involves the oxidative hydrolysis of an amide of formula 4 to a diol of formula 5. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 7, Step A involves the oxidation of an aldehyde of formula 1 to obtain a carboxylic acid of formula 2. The oxidation is conducted in the presence of: 1) an oxidizing agent such as sodium chlorite; 2) a phosphate salt, preferably sodium dihydrogenphosphate; 3) a protic organic solvent, preferably an alcohol such as t-butanol; and 4) an alkene, preferably 2-methylpropene, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 8 hours, preferably for 1 hour.
Step B involves the acylation of an amine of formula 3 to obtain an amide of formula 4. The acylation is conducted in the presence of: 1) a carboxylic acid of formula 2; 2) a carboxylic acid coupling reagent, preferably a diimide such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and a suitable activating agent common to diimide coupling reactions, such as 1-hydroxybenzotriazole; and 3) a polar organic solvent, preferably a low molcular weight amide such as DMF, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 and 24 hours.
Step C involves the oxidative hydrolysis of an amide of formula 4 to a diol of formula 5. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 8, Step A involves the reductive amination of an aldehyde of formula 1 to obtain an amine of formula 3. The reductive amination is conducted in the presence of: 1) an amine of formula 2; 2) a reducing agent, preferably a hydride, more preferably a borohydride salt such as sodium borohydride; and 3) a polar organic solvent, preferably a lower alkanol such as ethanol, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably from 5xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 16 hours.
Step B involves the acylation of an amine of formula 3 to obtain an amide of formula 4. The acylation is conducted in the presence of: 1) a carboxylic acid of formula R2*CO2H where R2* is defined above; 2) a carboxylic acid coupling reagent, preferably a diimide such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and a suitable activating agent common to diimide coupling reactions, such as 1-hydroxybenzotriazole; and 3) a polar organic solvent, preferably a low molcular weight amide such as DMF, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 and 24 hours.
Step C involves the oxidative hydrolysis of an amide of formula 4 to a diol of formula 5. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 9, Step A involves the acylation of an amine of formula 1 to obtain a carbamate of formula 2. The acylation is conducted in the presence of: 1) a chloroformate of formula ClCO2R3* where R3* is defined above; 2) a weak base, preferably an amine such as triethylamine; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 40xc2x0 C., preferably at 5xc2x0 C., for a period of between 1 and 24 hours.
Step B involves the oxidative hydrolysis of a carbamate of formula 2 to a diol of formula 3. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 10, Step A involves the olefination of an aldehyde of formula 1 with a phosphonium salt of formula 2 to obtain an alkene of formula 3. The olefination is conducted in the presence of: 1) a strong base, preferably an alkali metal salt such as potassium hexamethyldisilazide or butyllithium; and 2) an inert organic solvent, preferably a hydrocarbon such as toluene, or an ether such as tetrahydrofuran, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step B involves the oxidative hydrolysis of an alkene of formula 3 to a diol of formula 4. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 11, Step A involves the olefination of an aldehyde of formula 1 with a phosphonate of formula 2 to obtain an olefin of formula 3. The olefination is conducted in the presence of: 1) a strong base, preferably a potassium salt such as potassium hexamethyldisilazide; 2) a crown ether such as 18-crown-6; and 3) an inert organic solvent, preferably a hydrocarbon such as toluene, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step B involves the oxidative hydrolysis of an alkene of formula 3 to a diol of formula 4. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
As to the individual steps in Scheme 12, Step A involves the olefination of an aldehyde of formula 1 with a phosphonate of formula 2 to obtain an olefin of formula 3. The olefination is conducted in the presence of: 1) a strong base, preferably a potassium salt such as potassium hexamethyldisilazide; 2) a crown ether such as 18-crown-6; and 3) an inert organic solvent, preferably a hydrocarbon such as toluene, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step B involves the oxidative hydrolysis of an alkene of formula 3 to a diol of formula 4. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour. 
The syntheses described in Scheme 13 may be applied when B* is not xe2x80x94CH(R1)CHxe2x95x90CHxe2x80x94CHxe2x95x90CH2 or xe2x80x94CH(R1)CHxe2x95x90CH2. As to the individual steps in Scheme 13, Step A involves the addition of a butene group to an aldehyde of formula 1 to obtain an alcohol of formula 2. The addition is conducted in the presence of: 1) a crotylboron reagent, preferably a chiral crotylboron reagent, more preferably a Z-crotylboronate derived from diisopropyl tartrate; 2) an optional drying reagent such as molcular sieves; and 3) an inert organic solvent, preferably a hydrocarbon such as toluene, at a temperature of between xe2x88x92100xc2x0 C. and 5xc2x0 C., preferably at xe2x88x9278xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step B involves the alkylation of an alcohol of formula 2 to obtain an alcohol of formula 3. The alkylation is conducted in the presence of: 1) a reactive benzylating reagent, preferably a reactive para-methoxybenzylating reagent such as p-methoxybenzyl-2,2,2-trichloroacetimidate; 2) a proton source, preferably a sulfonic acid such as pyridinium p-toluenesulfonate; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step C involves the two stage oxidative cleavage of an alcohol of formula 3 to obtain an aldehyde of formula 4. The first stage of the oxidative cleavage is conducted in the presence of: 1) a dihydroxylating reagent, preferably an osmium reagent such as osmium tetroxide; 2) a cooxidant such as N-morpholine-N-oxide; and 3) a mixture of aprotic polar and protic solvents such as a mixture of acetone, water, and t-butanol, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours. The second stage of the oxidative cleavage is conducted in the presence of: 1) a periodate salt such as sodium periodate; and 2) a mixture of aprotic polar and protic solvents such as a mixture of tetrahydrofuran and water, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step D involves the addition of a butene group to an aldehyde of formula 4 to obtain an alcohol of formula 5. The addition is conducted in the presence of: 1) a crotyl addition reagent, preferably a crotyltin reagent such as crotyltributyltin; 2) a Lewis acid such as borontrifluoride etherate; and 3) an inert organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 5xc2x0 C., preferably at xe2x88x9278xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours.
Step E involves the silylation of an alcohol of formula 5 to obtain a silyl ether of formula 6. The silylation is conducted in the presence of: 1) a silylating reagent, preferably a t-butyldimethylsilylating reagent such as t-butyldimethylsilyltriflate; 2) a weak base, preferably a nitrogen-containing base, more preferably a pyridine base such as 2,6-lutidine; and 3) an inert organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 5xc2x0 C., preferably at xe2x88x9220xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours. 
The syntheses described in Scheme 14 may be applied when B* is not xe2x80x94CH(R1)CHxe2x95x90CHxe2x80x94CHxe2x95x90CH2 or xe2x80x94CH(R1)CHxe2x95x90CH2. As to the individual steps in Scheme 14, Step A involves the two stage oxidative cleavage of an alkene of formula 1 to obtain an aldehyde of formula 2. The first stage of the oxidative cleavage is conducted in the presence of: 1) a dihydroxylating reagent, preferably an osmium reagent such as osmium tetroxide; 2) a cooxidant such as N-morpholine-N-oxide; and 3) a mixture of aprotic polar and protic solvents such as a mixture of acetone, water, and t-butanol, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours. The second stage of the oxidative cleavage is conducted in the presence of: 1) a periodate salt such as sodium periodate; and 2) a mixture of aprotic polar and protic solvents such as a mixture of tetrahydrofuran and water, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step B involves the reduction of an aldehyde of formula 2 to obtain an alcohol of formula 3. The reduction is conducted in the presence of: 1) a hydride reducing agent, preferably an aluminum hydride such as lithium aluminum hydride or diisobutylaluminum hydride, or a borohydride such as sodium borohydride; and 2) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours.
Step C involves the iodination of an alcohol of formula 3 to obtain an iodide of formula 4. The iodination is conducted in the presence of: 1) an iodinating reagent such as I2; 2) a phosphorus-containing compound such as triphenylphoshine; 3) a weak base, preferably a weak nitrogen-containing base such as imidazole; and 4) a polar organic solvent, preferably an ester such as ethyl acetate, at a temperature of between xe2x88x9210xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours.
Step D involves the two stage hydroxylation of an alkene of formula 1 to obtain an alcohol of formula 5. The first stage of the hydroxylation is conducted in the presence of: 1) a borane such as 9-borabicyclo[3.3.1]nonane; and 2) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x9210xc2x0 C. and 40xc2x0 C., preferably at 0xc2x0 C., for a period of between 1 hour and 48 hours, preferably for 24 hours. The second stage of the hydroxylation is conducted in the presence of: 1) an oxidant, preferably a peroxide such as hydrogen peroxide; 2) a strong alkali base, preferably a hydroxide base such as sodium hydroxide; and 3) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x9210xc2x0 C. and 40xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 8 hours, preferably for 1 hour.
Step E involves the iodination of an alcohol of formula 5 to obtain an iodide of formula 6. The iodination is conducted in the presence of: 1) an iodinating reagent such as 12; 2) a phosphorus-containing compound such as triphenylphoshine; 3) a weak base, preferably a weak nitrogen-containing base such as imidazole; and 4) a polar organic solvent, preferably an ester such as ethyl acetate, at a temperature of between xe2x88x9210xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours.
Step F involves the two stage iodination of an alkene of formula 1 to obtain an iodide of formula 6. The first stage of the iodination is conducted in the presence of: 1) a borane such as 9-borabicyclo[3.3.1]nonane; and 2) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x9210xc2x0 C. and 40xc2x0 C., preferably at 0xc2x0 C., for a period of between 1 hour and 48 hours, preferably for 24 hours. The second stage of the iodination is conducted in the presence of I2; and 2) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x9210xc2x0 C. and 40xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 8 hours.
Step G involves the phoshine addition reaction of an iodide of formula 6 to obtain a phosphonium iodide salt of formula 7. The phoshine addition reaction is conducted in the presence of: 1) a phosphorus reagent such as triphenylphosphine; 2) a base, preferably an amine base such as diisopropylethylamine; and 3) an organic solvent, preferably a polar aprotic solvent such as acetonitrile, at a temperature of between 25xc2x0 C. and 150xc2x0 C., preferably at 90xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 18 hours. 
As to the individual steps in Scheme 15, Step A involves the alkylation of an alcohol of formula 1 to obtain an ether of formula 2. The alkylation is conducted in the presence of: 1) a reactive benzylating reagent, preferably a reactive para-methoxybenzylating reagent such as p-methoxybenzyl-2,2,2trichloroacetimidate; 2) a proton source, preferably a sulfonic acid such as pyridinium p-toluenesulfonate; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step B involves the reduction of an ether of formula 2 to obtain an alcohol of formula 3. The reduction is conducted in the presence of: 1) a metal hydride, preferably an aluminum hydride such as lithium aluminum hydride or diisobutylaluminum hydride; and 2) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 10xc2x0 C., preferably from xe2x88x9278xc2x0 C. to 0xc2x0 C., for a period of between 10 minutes and 8 hours, preferably for 2 hours.
Step C involves the alkylation of an alcohol of formula 3 to obtain an ether of formula 4. The alkylation is conducted in the presence of: 1) an alcohol of formula A*OH, where A* is as described above; 2) a coupling reagent such as diethyl azodicarboxylate; 3) a phosphine such as triphenylphosphine; and 4) a polar organic solvent, such tetrahydrofuran, at a temperature of between xe2x88x9278xc2x0 C. and 60xc2x0 C., preferably between xe2x88x9220xc2x0 C. and 40xc2x0 C., for a period of between 2 and 72 hours, preferably for 16 hours.
Step D involves the oxidative hydrolysis of an ether of formula 4 to an alcohol of formula 5. The oxidative hydrolysis is conducted in the presence of: 1) an oxidant, preferably a quinone such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 2) water; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour.
Step E involves the oxidation of an alcohol of formula 5 to obtain an aldehyde of formula 6. The oxidation is conducted in the presence of: 1) an oxidizing reagent, preferably a mild oxidizing reagent such as the combinations of oxalyl chloride, DMSO and triethylamine; sulfur trioxide-pyridine complex, DMSO and triethylamine; and 2,2,6,6-tetramethyl-1-piperidinyloxy free radical and diacetoxyiodobenzene; and 2) an inert organic solvent, preferably a polar organic solvent such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours. 
As to the individual steps in Scheme 16, Step A involves the palladium-mediated coupling of an alkyl zinc bromide of formula 1 and a vinyl iodide of formula 2 to obtain an alkene of formula 3. The palladium-mediated coupling is conducted in the presence of: 1) a palladium reagent such as tetrakis(triphenylphosphine)palladium(0); and 2) a polar organic solvent, preferably an ether such as diethyl ether or tetrahydrofuran, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., for a period of between 1 hour and 72 hours.
Step B involves the amidation of an alkene of formula 3 to obtain an amide of formula 4. The amidation is conducted in the presence of: 1) an O,N-dialkylated hydroxylamine such as N,N-dimethylhydroxylamine hydrochloride; 2) an organometallic reagent, preferably an alkylmagnesium halide or a trialkylaluminum reagent such as trimethylaluminum; and 3) an organic solvent, preferably a hydrocarbon such as toluene or hexane, or a mixture of the two, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 1 hour.
Step C involves the addition reaction of an amide of formula 4 with a metalloalkane, preferably an alkyllithium or alkylmagnesium halide reagent such as ethylmagnesium bromide, to obtain a ketone of formula 5. The addition reaction is conducted in the presence of a polar organic solvent such as tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 0xc2x0 C., preferably at xe2x88x9278xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 4 hours.
Step D involves the addition reaction of a ketone of formula 5 with an aldehyde of formula B*CHO, where B is as described above, to obtain a hydroxyketone of formula 6. The addition reaction is conducted in the presence of: 1) a Lewis acid, preferably a boron or titanium reagent such as trisopropoxytitanium chloride; and 2) a polar organic solvent, preferably an ether such as diethyl ether or tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 0xc2x0 C., preferably at xe2x88x9278xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 16 hours.
Step E involves the alkylation of a hydroxyketone of formula 6 to obtain an ether of formula 7. The alkylation is conducted in the presence of: 1) a reactive benzylating reagent, preferably a reactive para-methoxybenzylating reagent such as p-methoxybenzyl-2,2,2-trichloroacetimidate; 2) a proton source, preferably a sulfonic acid such as pyridinium p-toluenesulfonate; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 25xc2x0 C., preferably at 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step F involves the reduction of an ether of formula 7 to obtain an alcohol of formula 8. The reduction is conducted in the presence of: 1) a reducing agent, preferably an aluminum hydride or borohydride, such as lithium tri-t-butoxyaluminum hydride; 2) a polar organic solvent, preferably an ether such as diethyl ether or tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 0xc2x0 C., preferably at xe2x88x9278xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 16 hours.
Step G involves the silylation of an alcohol of formula 8 to obtain an ether of formula 9. The silylation is conducted in the presence of: 1) a silylating reagent, preferably a t-butyldimethylsilylating reagent such as t-butyldimethylsilyltriflate; 2) a weak base, preferably a nitrogen-containing base, more preferably a pyridine base such as 2,6-lutidine; and 3) an inert organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 5xc2x0 C., preferably at xe2x88x9220xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours. 
As to the individual steps in Scheme 17, Step A concerns the carbamoylation of the olefin of formula 1 with a an isocyanate either of formula C*NCO or Cl3C(O)NCO to give a carbamate of formula 2. In the case of using C*NCO, the carbamoylation is conducted in the presence of a Lewis acid such as Bu2Sn(OAc)2 or a weak base such as triethylamine, in a polar aprotic solvent, preferably a halogenated solvent such as methylene chloride at a temperature of between xe2x88x9220xc2x0 C. and 100xc2x0 C., preferably between 0xc2x0 C. and 50xc2x0 C., for a period of between 5 minutes and 72 hours, preferably between 1 hour and 24 hours. In the case using Cl3C(O)NCO, which produces substituted polyketides of formula I where Cxe2x95x90H, the carbamoylation is conducted in the presence of a polar aprotic solvent, preferably a halogenated solvent such as methylene chloride at a temperature of between xe2x88x9220xc2x0 C. and 100xc2x0 C., preferably at 25xc2x0 C., for a period of between 5 minutes and 72 hours, preferably between 1 hour and 8 hours; the work-up of this step is conducted in the presence of a protic organic solvent, preferably an alcohol such as methanol, in the presence of a base, for example, a carbonate such as potassium carbonate, at a temperature of between between 0xc2x0 C. and 100xc2x0 C., preferably at 25xc2x0 C., for a period of between 5 minutes and 72 hours, preferably between 1 hour and 8 hours.
Step B involves the reduction of a carbamate of formula 2 to obtain an alcohol of formula 3. The reduction is conducted in the presence of: 1) a reducing agent, preferably an aluminum hydride or borohydride, such as lithium tri-t-butoxyaluminum hydride; and 2) a polar organic solvent, preferably an ether such as diethyl ether or tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 0xc2x0 C., preferably at xe2x88x9278xc2x0 C., for a period of between 1 hour and 72 hours, preferably for 16 hours.
Step C involves the silylation of an alcohol of formula 3 to obtain an ether of formula 4. The silylation is conducted in the presence of: 1) a silylating reagent, preferably a t-butyldimethylsilylating reagent such as t-butyldimethylsilyltriflate; 2) a weak base, preferably a nitrogen-containing base, more preferably a pyridine base such as 2,6-lutidine; and 3) an inert organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 5xc2x0 C., preferably at xe2x88x9220xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours. 
As to the individual steps in Scheme 18, Step A involves the oxidation an aldehyde of formula 1 to obtain a carboxylic acid of formula 2. The oxidation is conducted in the presence of: 1) an oxidizing agent such as sodium chlorite; 2) a phosphate salt, preferably sodium dihydrogenphosphate; 3) a protic organic solvent, preferably an alcohol such as t-butanol; and 4) an alkene, preferably 2-methylpropene, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 8 hours, preferably for 1 hour.
Step B involves the reductive amination of an aldehyde of formula 1 to obtain an amine of formula 3. The reductive amination is conducted in the presence of: 1) an amine of formula R5NH2, where R5 is as defined above; 2) a reducing agent, preferably a hydride, more preferably a borohydride salt such as sodium borohydride; and 3) a polar organic solvent, preferably a protic organic solvent such as ethanol, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably from 5xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 16 hours.
Step C involves the azidation of an iodide of formula 4 to obtain an azide of formula 5. The azidation is conducted in the presence of: 1) an azide salt such as sodium azide; and 2) a polar organic solvent such as DMF, at a temperature of between 25xc2x0 C. and 150xc2x0 C., preferably at 90xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 16 hours.
Step D involves the reduction of an azide of formula 5 to obtain an amine of formula 6. The azidation is conducted in the presence of: 1) a reducing agent, preferably a phosphine such as triphenylphoshine in the presence of water; and 2) a polar organic solvent such as tetrahydrofuran, at a temperature of between 0xc2x0 C. and 100xc2x0 C., preferably from 25xc2x0 C. to 60xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 16 hours. 
As to the individual steps in Scheme 19, Step A involves the reduction of an aldehyde of formula 1 to obtain an alcohol of formula 2. The reduction is conducted in the presence of: 1) a hydride reducing agent reagent, preferably an aluminum hydride such as lithium aluminum hydride or diisobutylaluminum hydride, or a borohydride such as sodium borohydride; and 2), a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours.
Step B involves the silylation of an alcohol of formula 2 to obtain a silyl ether of formula 3. The silylation is conducted in the presence of: 1) a silylating reagent, preferably a t-butyldimethylsilylating reagent such as t-butyldimethylsilyltriflate; 2) a weak base, preferably a nitrogen-containing base, more preferably a pyridine base such as 2,6-lutidine; and 3) an inert organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 5xc2x0 C., preferably at xe2x88x9220xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours.
Step C involves the reductive hydrolysis of a silyl ether of formula 3 to obtain an alcohol of formula 4. The reductive hydrolysis is conducted in the presence of: 1) a Lewis acidic hydride, preferably an aluminum hydride such as diisobutylaluminumhydride; and 2) a polar organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 5xc2x0 C., preferably at xe2x88x9278xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 1 hour.
Step D involves the oxidation of an alcohol of formula 4 to obtain an aldehyde of formula 5. The oxidation is conducted in the presence of: 1) an oxidizing reagent, preferably a mild oxidizing reagent such as the combinations of oxalyl chloride, DMSO and triethylamine; sulfur trioxide-pyridine complex, DMSO and triethylamine; and 2,2,6,6-tetramethyl-1-piperidinyloxy free radical and diacetoxyiodobenzene; and 2) an inert organic solvent, preferably a polar organic solvent such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step E involves the olefination of an aldehyde of formula 5 to obtain a diene of formula 6. The olefination is conducted in the presence of: 1) a halogenated silyl propene such as 1-bromo-1-trimethylsilyl-2-propene; 2) a chromium(II) reagent such as chromium(II)chloride; and 3) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 40xc2x0 C., preferably at 20xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step F involves the hydrolysis of a diene of formula 6 to obtain an alcohol of formula 7. The hydrolysis is conducted in the presence of: 1) a protic acid, preferably a hydrogen halide such as hydrochloric acid; and 2) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x9210xc2x0 C. and 40xc2x0 C., preferably at 20xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 1 hour.
Step G involves the oxidation of an alcohol of formula 7 to obtain an aldehyde of formula 8. The oxidation is conducted in the presence of: 1) an oxidizing reagent, preferably a mild oxidizing reagent such as the combinations of oxalyl chloride, DMSO and triethylamine; sulfur trioxide-pyridine complex, DMSO and triethylamine; and 2,2,6,6-tetramethyl-1-piperidinyloxy free radical and diacetoxyiodobenzene; and 2) an inert organic solvent, preferably a polar organic solvent such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step H involves the propionate addition reaction of an aldehyde of formula 8 to obtain an imide of formula 10. The propionate addition reaction is conducted in the presence of: 1) a propanimide of formula 9; 2) a Lewis acid, preferably a boron-containing Lewis acid such as dibutylborontriflate; 3) a weak base, preferably an amine base such as triethylamine; and 4) an inert organic solvent, preferably a polar organic solvent such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 20xc2x0 C., preferably from xe2x88x9278xc2x0 C. to 0xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours.
Step I involves the silylation of an alcohol of formula 10 to obtain a silyl ether of formula 11. The silylation is conducted in the presence of: 1) a silylating reagent, preferably a t-butyldimethylsilylating reagent such as t-butyldimethylsilyltriflate; 2) a weak base, preferably a nitrogen-containing base, more preferably a pyridine base such as 2,6-lutidine; and 3) an inert organic solvent, preferably a halogenated hydrocarbon such as methylene chloride, at a temperature of between xe2x88x92100xc2x0 C. and 5xc2x0 C., preferably at xe2x88x9220xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 2 hours. 
As to the individual steps in Scheme 20, Step A involves the hydrolysis of an imide of formula 1 to obtain a carboxylic acid of formula 2. The hydrolysis is conducted in the presence of: 1) a strong base, preferably a hydroxide salt such as lithium hydroxide; 2) an oxidant, preferably a peroxide such as hydrogen peroxide; and 3) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9210xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 18 hours.
Step B involves the reduction of an imide of formula 1 to obtain an alcohol of formula 3. The reduction is conducted in the presence of: 1) a hydride reducing agent such as lithium borohydride; 2) a protic organic solvent, preferably a lower alkanol such as ethanol; and 3) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably at 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 18 hours.
Step C involves the acylation of an imide of formula 1 to obtain an amide of formula 4. The acylation is conducted in the presence of: 1) N,O-dimethylhydroxylamine hydrochloride; 2) an organoaluminum reagent such as trimethylaluminum; and 3) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x9278xc2x0 C. and 40xc2x0 C., preferably at xe2x88x9220xc2x0 C., for a period of between 10 minutes and 8 hours, preferably for 2 hours.
Step D involves the oxidation of an alcohol of formula 3 to obtain an aldehyde of formula 5. The oxidation is conducted in the presence of: 1) an oxidizing reagent, preferably a mild oxidizing reagent such as the combinations of oxalyl chloride, DMSO and triethylamine; sulfur trioxide-pyridine complex, DMSO and triethylamine; and 2,2,6,6-tetramethyl-1-piperidinyloxy free radical and diacetoxyiodobenzene; and 2) an inert organic solvent, preferably a polar organic solvent such as methylene chloride, at a temperature of between xe2x88x9278xc2x0 C. and 40xc2x0 C., preferably from xe2x88x9220xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 3 hours.
Step E involves the reduction of an amide of formula 4 to obtain an aldehyde of formula 5. The reduction is conducted in the presence of: 1) a metal hydride, preferably an aluminum hydride such as lithium aluminum hydride or diisobutylaluminum hydride; and 2) a polar organic solvent, preferably an ether such as tetrahydrofuran, at a temperature of between xe2x88x92100xc2x0 C. and 10xc2x0 C., preferably from xe2x88x9278xc2x0 C. to 0xc2x0 C., for a period of between 10 minutes and 8 hours, preferably for 2 hours.
Step F involves the reductive amination of an aldehyde of formula 5 to obtain an amine of formula 6. The reductive amination is conducted in the presence of: 1) an amine of formula R5NH2, where R5 is as defined above; 2) a reducing agent, preferably a hydride, more preferably a borohydride salt such as sodium borohydride; and 3) a polar organic solvent, preferably a protic organic solvent such as ethanol, at a temperature of between 0xc2x0 C. and 40xc2x0 C., preferably from 5xc2x0 C. to 25xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 16 hours.
Step G involves the mesylation of an alcohol of formula 3 to obtain a mesylate of formula 7. The mesylation is conducted in the presence of: 1) methanesulfonyl chloride; 2) a base, preferably an amine base such as triethylamine; and 3) a polar organic solvent, preferably a halogenated hydrocarbon such as such as methylene chloride, at a temperature of between xe2x88x9220xc2x0 C. and 40xc2x0 C., preferably from 0xc2x0 C. to 5xc2x0 C., for a period of between 10 minutes and 8 hours, preferably for 2 hours.
Step H involves the azidation of a mesylate of formula 7 to obtain an azide of formula 8. The azidation is conducted in the presence of: 1) an azide salt such as sodium azide; and 2) a polar organic solvent such as DMF, at a temperature of between 25xc2x0 C. and 150xc2x0 C., preferably at 90xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 16 hours.
Step I involves the reduction of an azide of formula 8 to obtain an amine of formula 9. The azidation is conducted in the presence of: 1) a reducing agent, preferably a phosphine such as triphenylphoshine in the presence of water; and 2) a polar organic solvent such as tetrahydrofuran, at a temperature of between 0xc2x0 C. and 100xc2x0 C., preferably from 25xc2x0 C. to 60xc2x0 C., for a period of between 10 minutes and 48 hours, preferably for 16 hours.
Although the product of each reaction described above may, if desired, be purified by conventional techniques such as chromatography or recrystallization (if a solid), the crude product of one reaction is advantageously employed in the following reaction without purification.
As is evident to those skilled in the art, compounds of formula I contain asymmetric carbon atoms. It should be understood, therefore, that the individual stereoisomers are contemplated as being included within the scope of this invention.
As indicated above, all of the compounds of formula I are anti-tumor agents and are, therefore, useful in inhibiting the growth of various lymphomas, sarcomas, carcinomas, myelomas, and leukemia cell lines. The anti-tumor activity of the compounds of formula I may be demonstrated employing the Anchorage Dependent Growth Monolayer Assay (ADGMA) which measures the growth inhibitory effects of test compounds on proliferation of adherent cell monolayers. This assay was adapted from the 60 cell line assay used by the National Cancer Institute (NCI) with the following modifications: 1) four cell lines representative for the important tumor types, viz., MIP 101 colon carcinoma, HCT 116 colon carcinoma, 1A9 ovarian carcinoma and 1A9PTX22 ovarian carcinoma, were utilized; and 2) a tetrazolium derivative, viz., MTT, was utilized to determine cell density.
The ADGMA compares the number of viable cells following a 3-day exposure to a test compound relative to the number of cells present at the time the test compound was added. Cell viability is measured using a tetrazolium derivative, viz., 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) that is metabolically reduced in the presence of an electron coupling agent (PMS; phenazine methosulfate) by viable cells to a water-soluble formazan derivative. The absorbance at 540 nm (A540) of the formazan derivative is proportional to the number of viable cells. The IC50 for a test compound is the concentration of compound required to reduce the final cell number to 50% of the final control cell number. If cell proliferation is inhibited, the assay further defines compounds as cytostatic (cell number after 3-day compound incubation greater than cell number at time of compound addition) or cytotoxic (cell number after 3-day compound incubation less than cell number at time of compound addition).
The HCT 116 colon carcinoma cell line was obtained from the American Type Culture Collection (ATCC, Rockville, Md.). The MIP 101 colon carcinoma cell line was obtained from Dr. Robert Kramer (Bristol Meyers Squibb) and was previously described (Niles R M, Wilhelm S A, Steele G D JR, Burke B, Christensen T, Dexter D, O""Brien M J, Thomas P, Zamcheck N. Isolation and characterization of an undifferentiated human colon carcinoma cell line (MIP-101). Cancer Invest. 1987;5(6):545-52.). The 1A9 and the 1A9PTX22 ovarian tumor cell lines were obtained from Dr. Tito Fojo, Medicine Branch, Division of Clinical Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Md. 20892. The 1A9 is a clone of the ovarian carcinoma cell line, A2780 (Giannakakou P, Sackett, D L, Kang Y-K, Zhan Z, Buters J T M, Fojo T, Poruchynsky M S. Paclitaxel-resistant human ovarian cancer cells have mutant xcex4-tubulins that impaired paclitaxel-driven polymerization. J. Biol. Chem. 1997, 272(4):17118-17125). The 1A9PTX22 subline was isolated as an individual clone from the 1A9 cell line in a single step selection by exposure to 5 ng/mL paclitaxel in the presence of 5 xcexcg/mL of verapamil. All cell lines were used between passages 4-20 following thawing. MIP-101 colon carcinoma, HCT 116 colon carcinoma, 1A9 ovarian carcinoma and 1A9PTX22 ovarian carcinoma cell lines are maintained and plated in RPMI 1640 medium containing 10% fetal bovine serum.
Cells are trypsinized and counted using a hemacytometer to determine cell concentrations. Cells were then plated in their respective maintenance media (200 xcexcL/well) in 96-well plates at the following concentrations: MIP-101, 2000 cells/well; HCT 116, 2000 cells/well; 1A9, 10000 cells/well; and 1A9PTX22, 10000 cells/well. The number of cells/well was determined in preliminary experiments, and resulted in 75-90% of confluency by day 4 after plating. Initial cell densities, assayed one day after plating, are roughly 0.10-0.20 A540 absorbance units greater than the media blank. Ninety-six well plates were seeded on day 0 and the test compounds are added on day 1. A xe2x80x9ctime 0xe2x80x9d plate was created that received media only in row A and one cell line/row in rows B-E. The xe2x80x9ctime 0xe2x80x9d plate was processed 24 hours after plating (at the time when drugs were added to experimental plates), as follows: 5 micoliters of the MTT stock solution (0.5 mg/mL in PBS) was added to each well and then incubated for three hours at 37xc2x0 C., 5% CO2, in a humidified environment. Media was then carefully and completely removed. Plates were allowed to dry in the dark. DMSO (dimethylsulfoxide) was added to each well (100 xcexcL/well) and plates were placed on an orbital shaker for 2 hours. Plates were read in the 96-well plate reader at 540 nm in a Molecular Devices plate reader utilizing Softmax Version 2.35 in absorbance mode-endpoint L-1, using DMSO as a blank. One day following plating, test compounds were added (in a final 1:10 dilution) to the test plates and subsequently serial diluted 10 times. Control plate received 1:10 dilution of the solvent (10% DMSO/90% RPMI 1640) only. Three days after addition of test compounds, all the experimental plates and the control plate were processed as described above for the xe2x80x9ctime 0xe2x80x9d plate. IC50 values are determined from graphs of percent net growth as a function of compound concentration. Percent net growth is calculated as (Cell+Drug A540xe2x88x92Initial 540/Cell+Drug Vehicle 540xe2x88x92Initial 540).
The following IC50 values (average of two or more separate experiments) in xcexcM were obtained:
The precise dosage of the compounds of formula I to be employed for inhibiting tumors depends upon several factors including the host, the nature and the severity of the condition being treated, the mode of administration and the particular compound employed. However, in general, satisfactory inhibition of tumors is achieved when a compound of formula I is administered parenterally, e.g., intraperitoneally, intravenously, intramuscularly, subcutaneously, intratumorally, or rectally, or enterally, e.g., orally, preferably intravenously or orally, more preferably intravenously at a single dosage of 1-300 mg/kg body weight per cycle (cycle=3-6 weeks) or, for most larger primates, a single dosage of 50-5000 mg per treatment cycle. A preferred intravenous single dosage per 3-6 week treatment cycle is 1-75 mg/kg body weight or, for most larger primates, a daily dosage of 50-1500 mg. A typical intravenous dosage is 45 mg/kg, once every three weeks.
Usually, a small dose is administered initially and the dosage is gradually increased until the optimal dosage for the host under treatment is determined. The upper limit of dosage is that imposed by side effects and can be determined by trial for the host being treated.
The compounds of formula I may be combined with one or more pharmaceutically acceptable carriers and, optionally, one or more other conventional pharmaceutical adjuvants and administered enterally, e.g., orally, in the form of tablets, capsules, caplets, etc. or parenterally, e.g., intraperitoneally or intravenously, in the form of sterile injectable solutions or suspensions. The enteral and parenteral compositions may be prepared by conventional means.
The compounds of formula I may be formulated into enteral and parenteral pharmaceutical compositions containing an amount of the active substance that is effective for inhibiting tumors, such compositions in unit dosage form and such compositions comprising a pharmaceutically acceptable carrier.
The compounds according to the invention can be administered alone or in combination with one or more other therapeutic agents, possible combination therapy taking the form of fixed combinations or the administration of a compound of the invention and one or more other therapeutic agents being staggered or given independently of one another, or the combined administration of fixed combinations and one or more other therapeutic agents. In particular, a compound of formula (I) can be administered, for example, in the case of tumor therapy in combination with chemotherapy, radiotherapy, immunotherapy, surgical intervention or a combination of these. Long-term therapy is equally possible as is adjuvant therapy in the context of other treatment strategies, as described above. Other possible treatments are therapy to maintain the patient""s status after tumor regression, or even chemopreventive therapy, for example, in patients at risk.
Therapeutic agents for possible combination are especially one or more anti-proliferative, cytostatic or cytotoxic compounds, for example, a chemotherapeutic agent or several agents selected from the group which includes, but is not limited to, an inhibitor of polyamine biosynthesis, an inhibitor of a protein kinase, especially of a serine/threonine protein kinase, such as protein kinase C, or of a tyrosine protein kinase, such as the EGF receptor tyrosine kinase, e.g., PKI166, the VEGF receptor tyrosine kinase, e.g., PTK787, or the PDGF receptor tyrosine kinase, e.g., STI571, a cytokine, a negative growth regulator, such as TGF-xcex2 or IFN-xcex2, an aromatase inhibitor, e.g., letrozole or anastrozole, an inhibitor of the interaction of an SH2 domain with a phosphorylated protein, anti-estrogens, topoisomerase I inhibitors, such as irinotecan, topoisomerase II inhibitors, microtubule active agents, e.g., paclitaxel, discodermolide or an epothilone, alkylating agents, anti-neoplastic anti-metabolites, such as gemcitabine or capecitabine, platin compounds, such as carboplatin or cisplatin, anti-angiogenic compounds, gonadorelin agonists, anti-androgens, bisphosphonates, e.g., AREDIA(copyright) or ZOMETA(copyright) and trastuzumab. The structure of the active agents identified by code nos., generic or trade names may be taken from the actual edition or the standard compendium xe2x80x9cThe Merck Indexxe2x80x9d or from databases, e.g., Patents International, e.g, IMS World Publications. The corresponding content thereof is hereby incorporated by reference.
The following examples show representative compounds encompassed by this invention and their synthesis. However, it should be clearly understood that it is for purposes of illustration only.